Human platelet glycoprotein IX: an adhesive prototype of leucine-rich glycoproteins with flank-center-flank structures.
Human platelet glycoprotein IX: an adhesive prototype of leucine-rich glycoproteins with flank-center-flank structures.
复制标题
人血小板糖蛋白 IX：富含亮氨酸的糖蛋白的粘附原型，具有侧翼-中心-侧翼结构。
DOI：
10.1073/pnas.86.17.6773
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发表时间：
1989
影响因子：
11.1
通讯作者：
Roth,GJ
中科院分区：
文献类型：
--
作者：
Hickey,MJ;Williams,SA;Roth,GJ
人血小板表面的糖蛋白（GP） Ib-IX复合物作为血管性血友病因子受体，介导血管性血友病因子依赖性血小板对血管的粘附。GPIX是一种相对较小的蛋白质（Mr, 17000），它可以为复合物的较大组分GPIb提供膜插入和定向（Mr, 165000）。通过抗体筛选，我们从噬菌体lambda gt11构建的人红白血病细胞cDNA文库中克隆出编码GPIX的cDNA。该cDNA序列缺乏5‘非翻译区和起始密码子，包含604个核苷酸，从5’端495个碱基开始，编码165个氨基酸，然后是3'端停止密码子和106个非编码碱基。通过Northern blot分析，GPIX cDNA与单个1.0千碱基的血小板poly(a)+ RNA杂交。翻译cDNA序列得到一个预测的蛋白质序列，从截断的5个氨基酸的假定信号序列开始，然后是17个氨基酸的序列，与完整GPIX的Edman降解直接确定的序列相匹配。预测的成熟GPIX氨基酸序列包括一个nh2末端胞质外结构域134个残基，一个跨膜结构域20个残基，6个胞质内残基和1个n -连接糖基化位点。GPIX含有一个富含亮氨酸的糖蛋白（LRG）序列，包含24个氨基酸，与GPIb和其他来自人类、果蝇和酵母的蛋白质中的保守LRG序列相似。在GPIX、GPIb和其他LRG家族的人类和果蝇成员中，大约有22个氨基酸的“侧翼”序列存在于LRG“中心”序列的NH2和/或COOH侧。侧翼-LRG中心-侧翼结构在LRG蛋白的进化和功能中的作用仍有待明确。
The glycoprotein (GP) Ib-IX complex on the surface of human platelets functions as the von Willebrand factor receptor and mediates von Willebrand factor-dependent platelet adhesion to blood vessels. GPIX is a relatively small (Mr, 17,000) protein that may provide for membrane insertion and orientation of the larger component of the complex, GPIb (Mr, 165,000). Using antibody screening, we cloned a cDNA encoding GPIX from a human erythroleukemia cell cDNA library constructed in phage lambda gt11. Lacking a 5' untranslated region and start codon, the cDNA sequence includes 604 nucleotides, beginning with 495 bases at the 5' end coding for 165 amino acids, followed by a stop codon and 106 noncoding bases at the 3' end. By Northern blot analysis, the GPIX cDNA hybridizes with a single 1.0-kilobase species of platelet poly(A)+ RNA. Translation of the cDNA sequence gives a predicted protein sequence beginning with a truncated putative signal sequence of 5 amino acid followed by a sequence of 17 amino acids matching that determined directly by Edman degradation of intact GPIX. The predicted amino acid sequence of mature GPIX includes an NH2-terminal extracytoplasmic domain of 134 residues, a transmembrane domain of 20 residues, 6 intracytoplasmic residues, and 1 N-linked glycosylation site. GPIX contains a leucine-rich glycoprotein (LRG) sequence of 24 amino acids similar to conserved LRG sequences in GPIb and other proteins from humans, Drosophila, and yeast. "Flanking" sequences of approximately 22 amino acids are present at the NH2 and/or COOH sides of the "central" LRG sequence(s) in GPIX, GPIb, and the other human and Drosophila members of the LRG family. The role of the flank-LRG center-flank structure in the evolution and function of the LRG proteins remains to be defined.